add links to djangorestframework-queryfields to docs (#4786)

docs/api-guide/serializers.md

@@ -1155,6 +1155,11 @@ The [html-json-forms][html-json-forms] package provides an algorithm and seriali
 
 [DRF-Base64][drf-base64] provides a set of field and model serializers that handles the upload of base64-encoded files.
 
+## QueryFields
+
+[djangorestframework-queryfields][djangorestframework-queryfields] allows API clients to specify which fields will be sent in the response via inclusion or exclusion query paramaters.  
+
+
 [cite]: https://groups.google.com/d/topic/django-users/sVFaOfQi4wY/discussion
 [relations]: relations.md
 [model-managers]: https://docs.djangoproject.com/en/stable/topics/db/managers/
@@ -1173,3 +1178,4 @@ The [html-json-forms][html-json-forms] package provides an algorithm and seriali
 [drf-dynamic-fields]: https://github.com/dbrgn/drf-dynamic-fields
 [drf-base64]: https://bitbucket.org/levit_scs/drf_base64
 [drf-serializer-extensions]: https://github.com/evenicoulddoit/django-rest-framework-serializer-extensions
+[djangorestframework-queryfields]: http://djangorestframework-queryfields.readthedocs.io/

docs/topics/third-party-resources.md

@@ -207,6 +207,7 @@ To submit new content, [open an issue][drf-create-issue] or [create a pull reque
 * [html-json-forms][html-json-forms] - Provides an algorithm and serializer to process HTML JSON Form submissions per the (inactive) spec.
 * [django-rest-framework-serializer-extensions][drf-serializer-extensions] -
   Enables black/whitelisting fields, and conditionally expanding child serializers on a per-view/request basis.
+* [djangorestframework-queryfields][djangorestframework-queryfields] - Serializer mixin allowing clients to control which fields will be sent in the API response.
 
 ### Serializer fields
 
@@ -370,3 +371,4 @@ To submit new content, [open an issue][drf-create-issue] or [create a pull reque
 [drf_tweaks]: https://github.com/ArabellaTech/drf_tweaks
 [drf-oidc-auth]: https://github.com/ByteInternet/drf-oidc-auth
 [drf-serializer-extensions]: https://github.com/evenicoulddoit/django-rest-framework-serializer-extensions
+[djangorestframework-queryfields]: https://github.com/wimglenn/djangorestframework-queryfields